This invention relates to devices for containing soft contact lenses during transport and storage.
The contact lens has gained wide acceptance as a replacement for conventional eyeglasses. Initially, contact lens were formed of hard material (hard lenses were often uncomfortable when worn by a significant number of users) thereby creating a need for soft lenses which more readily adapt to the geometric shape of the user. The hard lenses were stored in a variety of different containers some of which permitted them to be maintained in an asepticized environment. Since the lenses were rigid, they could be fixedly held against a curved receiving portion and stored for subsequent use.
One such device is shown in U.S. Pat. No. 3,298,502 to Schwartzman which positively urges a portion of the hard contact lens against a valve head to permit fluid flow within the container. FIG. 9 of the patent clearly shows the use of part of the lens to transmit force as the cap is rotated onto the threaded body. This device applies pressure to the lens, with the pressure being confined to a relatively small area of the lens and apparently rotates the lens while it is under pressure. This type of container is unsuitable for use with soft contact lenses wherein selective pressure results in dimensional change and the rotation under pressure is likely to scratch or otherwise damage the lens.
Another container for hard contact lenses is shown in U.S. Pat. No. 3,037,616 to Phipps wherein the hard lens is rotated on a carrier into position against a deformable pressure-exerting pad. The potential for scratching soft lenses is quite high with this type of device. Further, the device is not intended to permit the entire lens to be subject to the moistening of an aseptic fluid. This is likely to result in shrinkage of a soft lens during storage.
The U.S. Pat. No. 3,343,657 to Speshyock discloses separate baskets for each hard contact lens. Each basket is contained within a sealed container suitable for containing a fluid. In this device the lens is free to move within the basket as noted from FIG. 4 and is unsupported during storage. While unsupported, free-movement storage may be appropriate under normal conditions for hard lenses, a supporting surface and limited movement thereon is needed for soft contact lenses due to their ability to change shape when exposed to modest unbalanced forces and their susceptibility to scratching due to contact with semi-rigid materials such as utilized in this type of hard lens storage device.
A soft contact lens carrier is shown in West German Pat. No. 2,531,827 to Bausch & Lomb which is concerned with maintaining the soft lens moist during storage. This device utilizes positive pressure hold-down by means of a snap-fitted locking arm within the chamber. The device utilizes a number of different piece parts which have to be assembled for relative movement during normal operation, thereby increasing the cost to the user. This type of carrier requires the user to perform several steps in removing the lens. Further, the release of the snap-fit locking device appears likely to carry the lens from its customary location making it difficult to locate for the user. The support structure for the lens is located in the cap rather than in the body so that any dislodging of the lens due to the removal of the locking mechanism has a greater potential for loss of the lens than would otherwise be the case.
Accordingly, it is an object of the invention to provide a simplified storage container for soft contact lenses which does not exert positive pressure directly on the lens while permitting the aseptic fluid to contact the lens.
In addition, the invention provides a support surface for the lens with an overlying flexible skirt to maintain its position on the surface as the container is transported.
A further object is the provision of a soft lens container that does not require internal locking means and separate operations to position the lens therein. The invention is directed to reducing potential for damage to the lens or loss of the lens during the removal of the lens from the container.
Another object is to provide a main storage body from which the lens is taken directly while in contact with the fluid solution for insertion by the user.